I am trying to make this:

A player walks up to a poster, when player hits a key(predefined) a mouse pointer shall appeare.So you can click the poster and a panel comes up. Then you use the mouse pointer to click buttons on panel. When finished bouth panel and mouse pointer is hidden again.

example:
if(key_h)
{some code to get the mouse pointer show}

Where do I put the code for the mouse pointer?
In the player code?
In the function or action that calls the panel whit buttons?
In the main code?
Or do I make a code page of its own, and just call it from there?